The role of neuronal dysfunction in the pathogenesis of spinal cord injury is poorly understood. Using standard electrophysiological techniques in the feline spinal contusion model, we intend to investigate the neurophysiological events in the region of injury, e.g., changes in membrane potential, synaptic transmission, and action potential conduction in myelinated fibers. With K ion-selective microelectrodes, we then plan to further dissect the cellular mechanisms of the observed phenomena and correlate our findings with ongoing blood flow, ultrastructural, and biochemical studies of spinal trauma. Our overall objective is to gain insight into the pathogenesis of spinal cord injury and apply this knowledge to the development of rational therapy in the clinical setting.